Thomas A. Ciulla

Vascular Endothelial Growth Factor–Induced Retinal Permeability Is Mediated by Protein Kinase C In Vivo and Suppressed by an Orally Effective β-Isoform–Selective Inhibitor

Increased vascular permeability and excessive neovas-cularization are the hallmarks of endothelial dysfunction, which can lead to diabetic macular edema and proliferative diabetic retinopathy in the eye. Vascular endothelial growth factor (VEGF) is an important mediator of ocular neovascularization and a known vasopermeability factor in nonocular tissues. In these studies, we demonstrate that intravitreal injection of VEGF rapidly activates protein kinase C (PKC) in the retina at concentrations observed clinically, inducing membrane translocation of PKC isoforms α, βII, and δ and > threefold increases in retinal vasopermeability in vivo. The effect of VEGF on retinal vascular permeability appears to be mediated predominantly by the β-isoform of PKC with >95% inhibition of VEGF-induced permeability by intravitreal or oral administration of a PKC β-isoform-selective inhibitor that did not inhibit histamine-mediated effects. These studies represent the first direct demonstration that VEGF can increase intraocular vascular permeability through activation of PKC in vivo and suggest that oral pharmacological therapies involving PKC β-isoform-selective inhibitors may prove efficacious for the treatment of VEGF-asso-ciated ocular disorders such as diabetic retinopathy.

INTRAVITREAL TRIAMCINOLONE ACETONIDE IN EXUDATIVE AGE-RELATED MACULAR DEGENERATION

Purpose: To examine the effects of intravitreal injection of 4.0 mg triamcinolone acetonide on the visual and clinical course of exudative age‐related macular degeneration. Methods: A randomized clinical trial of a single injection of triamcinolone acetonide into the vitreous cavity of experimental eyes at baseline versus observation of untreated subjects was performed in 27 patients followed up for 6 months. Inclusion criteria included exudative age‐related macular degeneration with subfoveal or occult choroidal neovascularization, and visual acuity between 20/40 and 20/400. Examination, acuity assessment, fundus photography, and fluorescein angiography were performed at baseline and at 3 and 6 months after enrollment. LogMAR visual acuity was compared between groups by a repeated measures analysis of variance model. Masked assessment of photographic studies was performed and groups were compared with Fishers exact test. Results: Visual acuity was significantly better in the treated group compared with control subjects at 3 and 6 months (P < 0.005). Fundus photography and angiography were more likely to show stability or improvement at 3 and 6 months in the treated group (P = 0.05). Intraocular pressure elevation was seen in 25% of treated patients, but was controlled with topical medications. Progression of cataract was more frequently seen in the treated group. Conclusions: Intravitreal triamcinolone acetonide may provide short‐term improvement in visual acuity and fundus findings in exudative macular degeneration. These findings must be considered preliminary and should be followed by multicenter, masked, placebocontrolled trials with long‐term follow‐up.Purpose:To examine the effects of intravitreal injection of 4.0 mg triamcinolone acetonide on the visual and clinical course of exudative age-related macular degeneration.Methods:A randomized clinical trial of a single injection of triamcinolone acetonide into the vitreous cavity of experimental eye

Bacterial endophthalmitis prophylaxis for cataract surgery: An evidence-based update☆

PURPOSE To assess commonly used cataract surgery bacterial endophthalmitis prophylaxis techniques based on a systematic literature review and evidence rating. CLINICAL RELEVANCE Prophylactic techniques to decrease the risk of bacterial endophthalmitis related to cataract surgery are commonly used, but the evidence justifying their use is unclear. LITERATURE REVIEWED A MEDLINE search of the literature published in English or with English abstracts from 1966 to 2000 was performed using various combinations of relevant key words. Eighty-eight peer-reviewed papers were identified and judged worthy of review on the basis of predefined criteria. RESULTS No prophylactic technique received the highest of three possible clinical recommendations (A, crucial to clinical outcome). Preoperative povidone-iodine preparation received the intermediate clinical recommendation (B, moderately important to clinical outcome). All other reported prophylactic interventions, including postoperative subconjunctival antibiotic injection, preoperative lash trimming, preoperative saline irrigation, preoperative topical antibiotics, antibiotic-containing irrigating solutions, and the use of intraoperative heparin, received the lowest clinical recommendation (C, possibly relevant but not definitely related to clinical outcome) based on weak and often conflicting evidence justifying their use. CONCLUSIONS With regard to bacterial endophthalmitis prophylaxis in cataract surgery, current literature most strongly supports the use of preoperative povidone-iodine antisepsis.

Two-year outcomes of the ranibizumab for edema of the mAcula in diabetes (READ-2) study.

OBJECTIVES To determine the long-term effects of ranibizumab (RBZ) in patients with diabetic macular edema (DME). DESIGN Prospective, randomized, interventional, multicenter clinical trial. PARTICIPANTS One hundred twenty-six patients with DME. METHODS Subjects were randomized 1:1:1 to receive 0.5 mg RBZ at baseline and months 1, 3, and 5 (group 1), focal or grid laser photocoagulation at baseline and month 3 if needed (group 2), or a combination of 0.5 mg RBZ and focal or grid laser at baseline and month 3 (group 3). Starting at month 6, if retreatment criteria were met, all subjects could be treated with RBZ. MAIN OUTCOME MEASURES The mean change from baseline in best-corrected visual acuity (BCVA) at month 24. RESULTS After the primary end point at month 6, most patients in all groups were treated only with RBZ, and the mean number of injections was 5.3, 4.4, and 2.9 during the 18-month follow-up period in groups 1, 2, and 3, respectively. For the 33 patients in group 1, 34 patients in group 2, and 34 patients in group 3 who remained in the study through 24 months, the mean improvement in BCVA was 7.4, 0.5, and 3.8 letters at the 6-month primary end point, compared with 7.7, 5.1, and 6.8 letters at month 24, and the percentage of patients who gained 3 lines or more of BCVA was 21, 0, and 6 at month 6, compared with 24, 18, and 26 at month 24. The percentage of patients with 20/40 or better Snellen equivalent at month 24 was 45% in group 1, 44% in group 2, and 35% in group 3. Mean foveal thickness (FTH), defined as center subfield thickness, at month 24 was 340 μm, 286 μm, and 258 μm for groups 1, 2, and 3, respectively, and the percentage of patients with center subfield thickness of 250 μm or less was 36%, 47%, and 68%, respectively. CONCLUSIONS Intraocular injections of RBZ provided benefit for patients with DME for at least 2 years, and when combined with focal or grid laser treatments, the amount of residual edema was reduced, as were the frequency of injections needed to control edema. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.

A simple method for DNA purification from peripheral blood

A new, simple, and inexpensive method for the rapid isolation of DNA from whole blood is described. Cell nuclei are prepared by lysis of cytoplasmic membranes and DNA within the nuclear pellet is dispersed with guanidine isothiocyanate and precipitated with isopropanol. DNA prepared in this way restricts completely and results in low backgrounds of nonspecific hybridization after Southern analysis. The yields of DNA are similar to those obtained by more tedious traditional procedures. Numerous genomic DNA samples can be prepared from whole blood in 2 h, thus facilitating gene linkage or other molecular studies in which large numbers of individuals are required.

A susceptibility locus for multiple sclerosis is linked to the T cell receptor β chain complex

Inheritance of T cell receptor beta chain (TCR beta) genes was analyzed in families of 40 sibling pairs concordant for the relapsing-remitting form of multiple sclerosis (MS). TCR beta haplotypes were determined by segregation analysis of polymorphic markers within the TCR beta complex. The mean proportion of TCR beta haplotypes identical by descent (IBD) inherited by MS sibling pairs was significantly increased compared with expected values (means test, p less than 0.004), whereas the distribution of haplotype sharing was random when MS patients were compared with their unaffected siblings. Furthermore, one allelic form of a TCR beta variable region gene segment was overrepresented on MS chromosomes compared with those parental chromosomes not transmitted to MS offspring both in the MS sibling pair families and in a second group of families containing only one individual affected with MS. These results demonstrate that a gene within the TCR beta complex or a closely linked locus influences susceptibility to MS.

Long-term Benefit of Sustained-Delivery Fluocinolone Acetonide Vitreous Inserts for Diabetic Macular Edema

OBJECTIVE To assess the efficacy and safety of intravitreal inserts releasing 0.2 μg/day (low dose) or 0.5 μg/day (high dose) fluocinolone acetonide (FA) in patients with diabetic macular edema (DME). DESIGN Two parallel, prospective, randomized, sham injection-controlled, double-masked, multicenter clinical trials. PARTICIPANTS Subjects with persistent DME despite at least 1 macular laser treatment were randomized 1:2:2 to sham injection (n = 185), low-dose insert (n = 375), or high-dose insert (n = 393). METHODS Subjects received study drug or sham injection at baseline and after 6 weeks were eligible for rescue laser. Based on retreatment criteria, additional study drug or sham injections could be given after 1 year. MAIN OUTCOME MEASURES The primary outcome was the percentage of patients with improvement from baseline best-corrected visual acuity (BCVA) in Early Treatment Diabetic Retinopathy Trial (ETDRS) letter score of 15 or more at month 24. Secondary outcomes included other parameters of visual function and foveal thickness (FTH). RESULTS The percentage of patients with improvement from baseline ETDRS letter score of 15 or more at month 24 was 28.7 and 28.6 in the low- and high-dose insert groups, respectively, compared with 16.2 in the sham group (P = 0.002 for each). Benefit occurred for both doses compared with sham at 3 weeks and all subsequent time points. The mean improvement in BCVA letter score between baseline and month 24 was 4.4 and 5.4 in the low- and high-dose groups, respectively, compared with 1.7 in the sham group (P = 0.02 and P = 0.016). At all time points compared with sham, there was significantly more improvement in FTH. Subjects requiring cataract surgery were more frequent in the insert groups, and their visual benefit was similar to that of subjects who were pseudophakic at baseline. Glaucoma requiring incisional surgery occurred in 3.7%, 7.6%, and 0.5% of the low-dose, high-dose, and sham groups, respectively. CONCLUSIONS Both low- and high-dose FA inserts significantly improved BCVA in patients with DME over 2 years, and the risk-to-benefit ratio was superior for the low-dose insert. This is the first pharmacologic treatment that can be administered by an outpatient injection to provide substantial benefit in patients with DME for at least 2 years.

Macular pigment optical density in a midwestern sample

OBJECTIVE To assess the distribution of the macular pigments (MPs) lutein (L) and zeaxanthin (Z) in a healthy sample more representative of the general population than past studies and to determine which dietary factors and personal characteristics might explain the large interindividual differences in the density of these MPs. DESIGN Prevalence study in a self-selected population. PARTICIPANTS Two hundred eighty healthy adult volunteers, consisting of 138 men and 142 women, between the ages of 18 and 50 years, recruited from the general population. METHODS MP optical density was measured psychophysically at 460 nm by use of a 1 degrees test field. Serum was analyzed for carotenoid and vitamin E content with reversed-phase high-performance liquid chromatography. Usual intakes of nutrients over the past year were determined by means of a food frequency questionnaire. MAIN OUTCOME MEASURES MP optical density. RESULTS Mean MP optical density measured 0.211 +/- 0.13, which is approximately 40% lower than the average reported in smaller, less representative studies. MP density was 44% lower in the bottom versus the top quintile of serum L and Z concentrations. Similarly, MP density was 33% lower in the bottom compared with the top quintile of L and Z intake. MP density was 19% lower in blue-grey-eyed subjects than in subjects with brown-black irises. When all variables were considered together in a general linear model of determinants of MP, statistically significant (P < 0.05) relationships were found between MP density and serum L and Z, dietary L and Z intake, fiber intake, and iris color. CONCLUSIONS These data suggest that MP values in this healthy adult population are lower than in smaller select samples. Moreover, these data indicate that MP is related to serum L and Z, dietary L and Z intake, fiber intake, and iris color.

Blebitis, Early EndophthalmitS, and Late Endophthalmitis after Glaucoma-filtering Surgery

PURPOSE The differentiating characteristics in blebitis and early and late endophthalmitis after glaucoma filtration surgery are reviewed. METHODS All admission records and operative reports, as well as available office notes, on patients with blebitis or bleb-associated endophthalmitis admitted to a large referral eye center from 1985 to 1995 were reviewed retrospectively. RESULTS Ten cases of blebitis and 33 cases of bleb-associated endophthalmitis were identified. One patient with blebitis progressed to culture-positive endophthalmitis. Of the 33 cases of bleb-associated endophthalmitis, there were 6 cases of early endophthalmitis (before postoperative week 6) and 27 cases of late endophthalmitis. In early endophthalmitis, Staphylococcus epidermidis was isolated on vitreous culture in 4 (67%) of 6 cases, whereas in late endophthalmitis, this organism was isolated in only 1 (4%) of 27 cases. In the 27 late cases, Streptococcus species and gram-negative organisms comprised 48% of isolates; of 33 cases of endophthalmitis, 15 (45%) demonstrated no growth on vitreous culture. Patients with endophthalmitis fared more poorly than those with blebitis in terms of visual outcome. CONCLUSIONS Because blebitis may be prodromal to endophthalmitis, aggressive antimicrobial therapy, perhaps with oral quinolones, is warranted. In addition, patients with blebitis should be observed closely to identify extension into the vitreous cavity so that intravitreous antibiotics can be administered in a timely fashion. Finally, clinicians should not extrapolate the results of the Endophthalmitis Vitrectomy Study to the postfiltration surgery endophthalmitis given the differing pathogenesis and unique spectrum of organisms.

Antivascular endothelial growth factor therapy for neovascular age-related macular degeneration

Purpose of review The most important recent advance in the treatment of neovascular age-related macular degeneration (AMD) is the development of antivascular endothelial growth factor (anti-VEGF) therapeutic agents that preserve and improve visual acuity by arresting choroidal neovascular growth and reducing vascular permeability. This review describes the current literature on the use of this therapeutic approach in the management of neovascular AMD. Recent findings Two anti-VEGF agents, pegaptanib sodium and ranibizumab, are currently approved by the United States Food and Drug Administration for the treatment of neovascular AMD. In addition, off-label use of a third anti-VEGF agent, bevacizumab, as a treatment option for neovascular AMD has become common worldwide. Other anti-VEGF agent strategies that have shown efficacy include small interfering RNA agents to silence the VEGF gene and receptor and the fusion protein VEGF trap. Summary The accumulation of preclinical and clinical evidence implicating VEGF-A in the pathogenesis of neovascular AMD has provided a strong rationale for the development of anti-VEGF agents for this disease. Anti-VEGF therapies have been used successfully in the clinic, encouraging their use in the treatment of other neovascular eye diseases.